<template>
  <div>
  <div class="shopcart">
    <div class="content" @click="toggletList">
      <div class="content-left">
        <div class="logo-wrapper">
          <div class="logo" :class="{'highlight':totalPrice>0}"><i class="icon-shopping_cart"></i></div>
          <div class="num" v-show="totalPrice>0">{{totalCount}}</div>
        </div>
        <div class="price" :class="{'highlight':totalPrice>0}">￥{{totalPrice}}</div>
        <div class="desc">另需配送费￥{{deliveryPrice}}元</div>
      </div>
      <div class="content-right" @click.stop="pay">
        <div class="pay" :class="payClass">{{payDesc}}</div>
      </div>
    </div>
    <div class="ball-container">
      <div v-for="ball,index in balls" :key="index">
        <transition name="drop" @before-enter="beforeDrop" @enter="dropping" @after-enter="afterDrop">
          <div class="ball" v-show="ball.show">
            <div class="inner inner-hook"></div>
          </div>
        </transition>
      </div>
    </div>
    <transition name="fold">
      <div class="shopcart-list" v-show="showlist">
        <div class="list-header">
          <h1 class="title">购物车</h1>
          <span class="empty" @click="empty">清空</span>
        </div>
        <div class="list-content" ref="listContent">
          <ul>
            <li class="food border-1px" v-for="food ,index in selectFoods">
              <span class="name">{{food.name}}</span>
              <div class="price">
                <span>￥{{food.price * food.count}}</span>
              </div>
              <div class="cartcontrol-wrapper">
                <cartcontrol :food="food" ></cartcontrol>
              </div>
            </li>
          </ul>
        </div>
      </div>
    </transition>
  </div>
  <transition name="mask"><div class="list-mask" v-show="showlist" @click="hideList"></div></transition>
  </div>
</template>

<script type="text/ecmascript-6">
  import cartcontrol from '../../components/cartcontrol/cartcontrol.vue';
  import BScroll from 'better-scroll';
    export default {
      props: {
        deliveryPrice: {
          type: Number
        },
        minPrice: {
          type: Number,
          default: 0
        },
        selectFoods: {
          type: Array
        }
      },
      data() {
        return {
          balls: [
            {
              show: false
            },
            {
              show: false
            },
            {
              show: false
            },
            {
              show: false
            },
            {
              show: false
            }
          ],
          dropBalls: [],
          fold: true
        };
      },
      computed: {
//        计算所有商品的总价
        totalPrice() {
          let total = 0;
          this.selectFoods.forEach((food) => {
            total += food.price * food.count;
          });
          return total;
        },
//        所有商品总和
        totalCount() {
          let count = 0;
          this.selectFoods.forEach((food) => {
            count += food.count;
          });
          return count;
        },
        payDesc() {
          if (this.totalPrice === 0) {
            return `￥${this.minPrice}元起送`;
          } else if (this.totalPrice < this.minPrice) {
            let diff = this.minPrice - this.totalPrice;
            return `还差￥${diff}元起送`;
          } else {
            return '去结算';
          }
        },
//        ：class绑定payclass变量
        payClass() {
          if (this.totalPrice < this.minPrice) {
            return 'not-enough';
          } else {
            return 'enough';
          }
        },
//        判断food列表是否显示
        showlist () {
//          如果没有买任何商品
          if (!this.totalCount) {
            this.fold = true;
            return false;
          }
          let show = !this.fold;
//          展示列表时，初始化
          if (show) {
            this.$nextTick(() => {
              if (!this.scroll) {
                this.scroll = new BScroll(this.$refs.listContent, {
                  click: true
                });
              } else {
                this.scroll.refresh();
              }
            });
          }
          return show;
        }
      },
      methods: {
//        小球抛物线动画
        drop(el) {
          for (let i = 0; i < this.balls.length; i++) {
            let ball = this.balls[i];
//            遍历小球，如果show为false；则将此球作为动画对象
            if (!ball.show) {
//              触发小球的动画
              ball.show = true;
//              把elment 保存
              ball.el = el;
//              把小球添加到dropBall
              this.dropBalls.push(ball);
              return;
            }
          }
        },
//       来回 折叠取反
        toggletList() {
          if (!this.totalCount) {
            return;
          }
          this.fold = !this.fold;
        },
        beforeDrop(el) {
          let count = this.balls.length;
          while (count--) {
            let ball = this.balls[count];
            if (ball.show) {
//              getBoundingClientRect 返回元素相对于视口的位置，left top 返回偏移量
              let rect = ball.el.getBoundingClientRect();
              let x = rect.left - 32;
              let y = -(window.innerHeight - rect.top - 22);
              el.style.display = '';
              el.style.webkitTransform = `translate3d(0,${y}px,0)`;
              el.style.transform = `translate3d(0,${y}px,0)`;
              let inner = el.getElementsByClassName('inner-hook')[0];
              inner.style.transform = `translate3d(${x}px,0,0)`;
              inner.style.webkitTransform = `translate3d(${x}px,0,0)`;
            }
          }
        },
        dropping(el) {
          /* eslint-disable no-unused-vars */
//        触发浏览器重构
          let rf = el.offsetHeight;
          this.$nextTick(() => {
            el.style.webkitTransform = 'translate3d(0,0,0)';
            el.style.transform = 'translate3d(0,0,0)';
            let inner = el.getElementsByClassName('inner-hook')[0];
            inner.style.transform = 'translate3d(0,0,0)';
            inner.style.webkitTransform = 'translate3d(0,0,0)';
          });
        },
        afterDrop(el) {
          let ball = this.dropBalls.shift();
          if (ball) {
            ball.show = false;
            el.style.display = 'none';
          }
        },
//        清空购物车
        empty() {
          this.selectFoods.forEach((food) => {
            food.count = 0;
          });
        },
        hideList() {
          this.fold = true;
        },
//        去结算
        pay() {
          if (this.totalPrice < this.minPrice) {
            return;
          }
          window.alert(`需要支付${this.totalPrice}元`);
        }
      },
      components: {
        cartcontrol
      }
    };
</script>

<style lang="stylus" rel="stylesheet/stylus">
  @import "../../common/stylus/mixin.styl";
  .shopcart
    position: fixed
    left: 0
    bottom: 0
    width: 100%
    height: 48px
    z-index: 50
    .content
      display: flex
      background: #141d27
      font-size: 0
      .content-left
        flex: 1
        .logo-wrapper
          display: inline-block
          position: relative
          top: -10px
          margin: 0 12px
          padding: 6px
          width: 56px
          height: 56px
          box-sizing: border-box
          vertical-align: top
          border-radius: 50%
          background: #141d27
          .logo
            width: 100%
            height: 100%
            border-radius: 50%
            background: rgb(43,52,60)
            text-align: center
            &.highlight
              background: rgb(0,160,220)
              .icon-shopping_cart
                color: rgb(255,255,255)
            .icon-shopping_cart
              font-size: 24px
              line-height: 44px
              color:rgb(128,133,138)
          .num
            position: absolute
            top: 0
            right: 0
            padding:0 6px
            line-height: 16px
            font-size: 9px
            font-weight: 700
            color: rgb(255,255,255)
            background: rgb(240,20,20)
            box-shadow: 0 4px 8px 0 rgb(0,0,0,.4);
            border-radius: 16px
        .price
          display: inline-block
          vertical-align: top
          margin-top: 12px
          line-height: 24px
          padding-right: 12px
          box-sizing: border-box
          border-right:1px solid rgba(255,255,255,.1)
          font-weight: 700
          font-size: 16px
          color: rgba(255,255,255,.4)
          &.highlight
            color: rgb(255,255,255)
        .desc
          display: inline-block
          vertical-align: top
          line-height: 24px
          margin: 12px 0 0 12px
          font-size: 10px
          color: rgba(255,255,255,.4)
      .content-right
        flex: 0 0 105px
        width: 105px
        .pay
          font-size: 12px
          height: 48px
          line-height: 48px
          color: rgba(255,255,255,.4)
          text-align: center
          font-weight: 700
          background: rgb(43,51,59)
          &.not-enough
            background: rgb(43,51,59)
          &.enough
            background: rgb(0,180,60)
            color: #fff
    .ball-container
      .ball
        position: fixed
        left: 32px
        bottom: 22px
        z-index: 200
        transition: all .4s cubic-bezier(0.49, -0.29, 0.75, 0.41)
        .inner
          width: 16px
          height: 16px
          border-radius: 50%
          background: rgb(0,160,220)
          transition: all .4s linear
    .shopcart-list
      position: absolute
      left: 0
      top: 0
      z-index: -1
      width: 100%
      transform: translate3d(0,-100%,0)
      &.fold-enter-active,&.fold-leave-active
       transition: all .5s
      &.fold-enter,&.fold-leave-active
        transform: translate3d(0,0,0)
      .list-header
        height: 40px
        line-height: 40px
        padding: 0 18px
        background: #f3f5f7
        border-bottom: 1px solid rgba(7,17,27,0.1)
        .title
          float: left
          font-size: 14px
          font-weight: 200
          color: rgb(7,17,27)
          line-height: 40px
        .empty
          float: right
          font-size: 12px
          color: rgb(0,160,220)
          line-height: 40px
      .list-content
        padding: 0 18px
        background-color: #fff
        max-height: 217px
        overflow: hidden
        .food
          position: relatve
          padding: 12px 0
          box-sizing: border-box
          border-1px(rgba(7,17,27,0.1))
          .name
            line-height: 24px
            font-size: 14px
            color: rgb(1,17,27)
          .price
            position: absolute
            right: 90px
            bottom: 12px
            line-height: 24px
            font-size: 14px
            font-weight: 700
            color: rgb(240,20,20)
          .cartcontrol-wrapper
            position: absolute
            right: 0
            bottom: 6px
  .list-mask
    position: fixed
    left: 0
    top: 0
    width: 100%
    height: 100%
    z-index: 40
    opacity: 1
    background: rgba(7,17,27,0.6)
    backdrop-filter: blur(10px)
    &.mask-enter-active,&.mask-leave-active
      transition: all .5s
    &.mask-enter,&.mask-leave-active
      opacity: 0
</style>
